I went to a lecture by a guy that was working on the project about 2 years ago. He said the only reason we aren't already using this in humans is that the 1000 or so needles they stick in the brain tends to cause infections and other indeterminable brain damage . . .

I can only imagine nano technology will improve to the point to where you can wear a hat that puts all the neddles in, but since they are so tiny it just tingles for the first 5 minutes of wearing the had.....